In the past, pressure-sensitive, reusable transfer elements were developed as an improvement over prior-known frangible transfer elements based upon hot-melt wax transfer layers. Such reusable transfer elements, both in ribbon and sheet form, were designed for reuse eight or more times in a typewriter or in a carbon form for manual use. For instance, ribbons of the reusable type were fed through a typewriter, in alternate forward and reverse directions, eight or more times and were then discarded when the ink supply diminished to the point that the images formed on the copy sheet lacked sufficient intensity or darkness, or when the ink layer began to flake or chip from its foundation.
Recently high speed typewriters have been developed which require the use of ribbons which are fed in only one direction, are overstruck or impressed at least about four times in each length of the ribbon corresponding to the width of two characters, and are discarded after a single pass. Such high speed typewriters, including the Xerox 800 electronic typewriter, and printers as disclosed in U.S. Pat. No. 3,954,163, carry an impression element which moves at a tremendous speed so that its duration of contact pressure with the typing ribbon is much less than in the case of conventional electric typewriters. Conventional reusable typewriter ribbons cannot be used successfully on such high speed typewriters because they do not produce typed images having good edge definition, absence of fill-in, sufficient sharpness and clarity and sufficient color intensity or uniformity of intensity and smudge-resistance under the conditions of use.